Pneumatic drop hammer



March 31. 1925. 1,531,491

G. P. MACREADY ET AL PNEUIATIC DROP HAMMER Filed. Nov. 2, 1922 2 Sheets-Sheet 1 7 auoentow Geo. P/Vac/"eaay 6: Hm. I Jay/7704M March 3l, 1925. 1,531,491

a. P.MACREADY ET AL PNIHIATIG DROP HAMMER Filed Nov. 2, 1922 2 Sheets-Sheet 2 anomtow Patented Mar. 31, 1925.

UNITED STATES PATENT OFFICE.

GmRGE P. MACREADY, OF PROVIDENCE, AND WILLIAIVI I. SEYMOUR, OF WEST BAR- RINGTON, RHODE ISLAND, ASSIGNORS TO FRANKLIN MACHINE COMPANY, OI PROVIDENCE, RHODE ISLAND, A CORPORATION OF RHODE ISLAND.

PNEUMATIC DROP HAMMER.

Application filed November 2, 1922. Serial No. 598,473.

To all whom it may concern:

Be it known that we, GEORGE P. MAC- READY, a citizen of the United States, and resident of Providence, in the county of Providence and State of Rhode Island, and lViLIJAM I. SEYMOUR, a citizen of the United States, and resident of West Barrington, in the county of Bristol and State of Rhode Island, have invented certain new and useful Improvements in Pneumatic Drop Hammers, of which the following is a -\pecification.

This invention relates to drop hammers and more particularly to hammers actuated by compressed air or other compressed fluid.

Some of the objects of the present invention are to provide an improved inlet and outlet valve for controlling the flow of compressed fluid; to provide an improved housing for such valves; to provide a chamber within the valve housing for the double purpose of conducting the fluid and maintaining the fluid as a cushion for the hammer )iston' and to rovide means for o enin I 7 P.

the inlet and outlet valve ports at the same speed.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of one form of mechanism embodying my invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the accompanying drawings:

Figure 1 shows a front elevation of one form of drop hammer embodying the features of the invention;

Figure 2 shows a top plan view, partly in section, of the valve mechanism of Figure 1; and

Figures 3 and 4 are sectional views taken on the lines 33 and 4-4 respectively of Figure 2.

The control mechanism for the drop hammer here illustrated is more fully described and is claimed in our co-pending application for pneumatic drop hammers, filed herewith, Serial No. 598,472.

Referring to the drawings, and more particularly to Figure 1, in which the inlet valve isassumed to be open and the hammer weight to be moving upwardly, one form of drop hammer comprises a supporting framework consisting of two upright, spaced, parallel members and 11 of suitable cast metal securely bolted to a table or Work bench 12. These I my be joined at their upper ends by a yoke 13 bolted thereto. The inner faces of the members 10 and 11 are machined to form guiding rails for a ram or weight 14 whose mass is made sufficiently great to perform the work of stamping out jewlery or other articles as may be required. The weight is provided with a perforated protruding car 15 for a purpose which will be subsequently set forth, and with a vertically extending connecting rod 16 which terminates in a piston 17. The piston reciprocates in a closely fitted cylinder 18 of suitable length, whose upper end is open to the atmosphere.

For raising the ram or hammer Weight 14 there is provided a source of compressed fluid such as a supply pipe 20 leading from a suitable air compressor of conventional design. The pipe 20 is branched to the upper and lower parts of the frame, there being provided suitable control valves in each of the branches, and a pressure gauge for indicating pressure, and a drain-cock for draining moisture therefrom. A branch 21 leads to the upper portion of the frame and more particularly to a valve mechanism positioned thereon, and shown in detail in Figure-2. The valve mechanism comprises a suitable housing 22 integral with the lower portion of the cylinder 18 and having its interior chamber 23 communicating with that portion of the interior of the cylinder 18 below the piston 17. The housing 22 is divided by a transverse partition 24 to form an exhaust chamber 25 which may be connected to atmosphere by a suitable exhaust pipe 26.

For moving the valve parts there is provided a shaft which may be 'journalled in a. suitable boss 31 in the housing 22 and which has a bearing in the transverse partition 24. One face of the partition 24, i. e. that towards the chamber 23, is machined, and against this surface there is positioned a perforated disc or valve 32 having its contacting face ground to match with the machined surface of the partition 24. The valve 32 is maintained in fixed position relative'to the shaft by a keyway, and is locked thereon by a suitable nut 33 and collar. Forming the outboard bearing for the rotatable shaft 30 there is provided a recessed flange 34 bolted to the housing 22 so as to enclose the chamber 23. The innerend face 35 of the flange 34 is machined, and against this face there is positioned a second perforated disc or valve 36 having its contacting face ground to match with the machined surface 35. The valve 36 includes an integral recess housing coextensive with a portion of the upper end of the shaft 30 which is securely fastened to the end of the shaft 30 in any suitable manner, asby a key. The recessed portion of the flange 34 is screw threaded for the reception of a nipple 37 into which the air inlet 21 is in turn screw threaded. All connections are securely sealed to prevent undesired escape of air.

For controlling the passage of air the disc 36 is provided with a series of spaced perforations, such as 40, and the inner face 35 of the flange 34 is provided with a similar series of perforations, such as 41, adaptedin one position of the disc 36 to register w th the perforations therein. As shown in-Figure 3 the valve port is open, since the respec tive perforations register, but by movement of the disc through anangle, the valve may be effectually closed. Similarly, the disc 32is provided with a series of perforations, such as 42, and the partitions 24 with a series of perforations, such as 43, arranged in one position of the disc 32 to register with theperforations therein. As shown in Figure 4 the valve port is closed, since the respective series of perforations are out of register, but by movement of the disc through an angle, so that the series of perforations are in alignment, the valve may be opened. The valves 32 and 36 and the shaft 30 may be rotated into such positions of closure or opening of the valves by a reciprocatory motion of a valve rod 44, loosely connected to a valve lever 45, by means of a clevis and pin connection, and this lever is mounted in fixed relation to the shaft30 on the protruding end thereof. The valve lever 45 has an integralhub 46 which is recessed for a friction spring 47.

The valve mechanism is effectually sealed against undesired escape of air in either position. For example, when the inlet ports are open and the outlet closed, the pressure of the air is exerted against the face of the disc 32 which is towards the chamber 23, and presses the valve disc 32 into intimate contact with the ground face of the partition 24. Similarly, when the outlet ports are open and the inlet is intended to be closed, the pressure of the air within the nipple 37 maintains the disc 36 securely seated. Thus it will be seen that the compressed fluid is used for the double purpose of operating the piston and seating the valves.

The lower end of the cylinder 18 is provided with a stuffing box 90 through which the rod 16 may slide, comprising a packin material held in place by a usual nut. lubricant may be su plied through a suitable oil hole Y91 and oil (Samuel 92 leading to the packing. Thus undesired escape of air is effectually prevented.

The valve mechanism may be assembled in the following manner: After the hub 31, and

partition 24 have been drilled for the shaft 30, the shaft is inserted in place,.and the disc 32 keyed thereto. The nut 33 isturned down into place. The flange 34 is then set, it having been drilled for the reception of the end of the shaft 30, and is bolted to the housing 22. The disc 36 is now keyed to the shaft 30. The spring 47 is placed on the shaft 30 outwardly of the housing wall, and the lever 45 is placed thereover and keyed to the shaft. The valve mechanism is adjusted to make good contact by arranging the discs 32 and 36 to seat snugly, and the nipple 37 and inlet pipe 21 screwed into place.

Suitable supports are provided for the valve rod 44, comprising a lug 50 and bush ing 51 at the upper end and a plunger 52 slidably held in a cylinder 53 at the lower end, as described in the applicants co-pending application Serial No..597,472, referred to. A branch pipe 54 connects the cylinder 53 with the source of air 20, and thus the lower portion of the cylinder forms a resilient cushion against any downward impact of the rod 4-4. ;The movement of the rod is thus rendered smooth and quiet. Co-operating with the upper face of the plunger 52 is a spring pressed latch 56 pivotally mounted on a suitable portion of the frame 11, so that the plunger 52 may be latched thereby in its lowermost position.

For unlocking the latch, there is provided a trip lever 60 pivotally mounted on-the frame 11 so that a portion thereof displaces the latch from engagement with the plunger 52. The free end of the lever 60 forms a convenient handle, as shown. An automatic lever 62 is pivotally mounted on a suitable bracket 63 on the frame member 11 so as to be substantially parallel with the trip lever 60. A link 64 interconnects these levers at intermediate portions thereof. matic lever 62 is pivotally connected with the lower end of an upright automatic rod 65, whose upper end is slidably supported in the lug 50. On an intermediate portion of the rod 65 there is. mounted a collar 66, which may be adjustably positioned thereon as by a suitable set screw. The arm 15 comes into engagement with the collar 66 at the upperend of the travel of the weight 14, and into engagement with an adjustable stop The auto- 67 at the lower end of the travel. The stop 67 may be adjustably positioned on the valve rod 44.

For preventing the dropping of the hammer weight at undesired times, and thus preventing ossible injury to workmen, there is provi ed an outlet valve lookin device comprising a pivoted beam rotataibly supported on the frame yoke 13. One end of the beam 70 is loosely connected to the upper end of a safety rod 71. The lower end of the rod 71 is loosely connected to an intermediate portion of a safety lever 72, one end of which is pivoted to the frame member 10 opposite the one having the trip'lever 60. The free end of the lever 72 is shaped to form a handle, as shown. The lever 72 and rod 71 may be locked in their upper position by a pivoted automatic safety lever 73 having an extension 74 upon which the lever 7 2 rides.

For cushioning the upper impact of the weight 14, there is provided a buffer comprising a compression spring 80, held in a desired position on the rod 16 by a split collar 81.

For maintaining the weight 14 in a predetermined position when the drop hammer is not in service, there is provided a pivoted lock lever 85 having a hooked end arranged to intercept the path of travel of the weight 14.

In operation, assuming that the operator intends to control the hammer manually, the

automatic lever 73 is left in the position shown. The supply of compressed air or other fluid being turned on, and the valve ports being in the position shown in Figures 3 and 4, air flows through the pipe 21, apertures 40 and 41, chamber 23 into the cylinder 18, raising the piston 17. The piston is stopped when the buffer spring 80 and collar 81 are pressed against the yoke 13, and is held in its extreme upper position by the column of compressed air in the cylinder 18. The operator then adjusts the work in the proper place.

en the operator desires the weight to fall, the right hand grasps the handle of lever 60 and moves it upwardly, thus releasing the latch 56. The compressed air supplied through branch pipe 54 then exerts an upwardly directed force upon the plunger 52, tending to force the rod 44 upwards. This force encounters the resistance of the cam 76 against the tooth 75, and the rod is not moved.

With the left hand, the operator raises the handle of the lever 72, thus moving the rod 71 upwardly, and the tooth 7 5 downwardly out of engagement with the cam 7 6. The rod 44 is thus permitted a limited upward movement, and the shaft 30 a limited rotary movement. The discs 32 and 36 are also rotated out of the position in which the inlet ports are open, that is the apertures 40 and 41 register, and into the position in which the outlet ports are open, that is, the respectwo series of apertures 42 and 43 register, and the inlet ports are eflectually closed.

The ram or weight 14 is thereby relieved of support and falls by force of gravity into contact with the work. The weight 14 may be provided with a suitable die or other tool in order to form the work into desired shape. When it is desired to have the weight rise and fall alternately a number of times success1vely, the collar 66 is suitably adjusted on the rod 65 so as to control the closing of the inlet and opening of outlet ports automatically. The lever 73 is' rotated in a clockwise direction and displaces the safety lever 72. The operation then is as follows:

Assuming the weight to be rising the ear 15 ultimately contacts with the collar 66, and thus raises the rod 65 sufliciently to raise the lever 62 and handle 60. This unlatches the trip 56 as in the case of manual operation, and thus permits the plunger 52 and rod 44 to move upwardly by force of the compressed air. Since the safety lever 72 is held in its uppermost position by the extension 74 of the automatic safety lever 73 which has been locked in its normal position, the tooth 75 does not retard operation of the valve mechanism. The inlet valve port is accordingly closed and the outlet port opened, permitting the weight to fall. As

soon as the ear 15 contacts with the collar I 67 and moves it downwardly, the outlet is closed and inlet port opened, as described for manual operation. The weight again rises and the operation is repeated continuously until the hammer is shut down or the automatic levers restored.

Thus it will be that We have provided a drop hammer mechanism reliably operated by a compressed medium such as air, in which the valve mechanism is of simple and rugged construction, and in which a minimum of moving parts are required. Furthermore, such moving parts are so mounted that the amount of wear is minimized and such wear as does occur is taken up by the parts. Thus a long life is assured and undesired leakage of the compressed fluid effectively prevented.

By means of the cushioning chamber the impact of the parts is minimized, the cushioning being obtained by utilizing a portion of the compressed medium supplied also for operating the hammer mechanism.

lVhile we have shown and described and have pointed out in the annexed claims certain novel features of our invention, it will be understood that various omissions, substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of our invention.

claim 1. In pneumatic hammer mechanism, a ram reciprocating in one plane, means for actuating the ram comprising a piston and cylinder, and a valve for controlling the flow of a compressed medium into and out of said cylinder comprising a rotatable shaft having a pair of spaced valve members secured thereto and rotatable therewith, each of said members controlling valve ports at difl'erent times.

2. In pneumatic hammer mechanism, a ram reciprocating in one plane, means for actuating the ram comprising a piston and cylinder, and a valve for controlling the flow of a compressed medium into and out of said cylinder comprising a rotatable shaft having a pairof spaced valve members secured thereto and rotatable therewith, each controlling valve ports at different times and means for actuating said valve.

3. In neumatic hammer mechanism, a ram reciprocating vertically, means for actuating the ram comprising a piston and cylinder, and a valve for controlling the flow of a compressed medium into and out of said cylinder comprising a rotatable shaft positioned at an angle to the line of movement of the ram and having a pair of spaced valve members secured thereto and rotatable therewith, each of said members controlling valve ports at different times.

4:. In a pneumatic hammer mechanism, a ram reciprocating in one plane, means for actuating the ram comprising a piston and cylinder, and a valve for controlling the flow of a compressed medium into and-out of said cylinder comprising a rotatable shaft having a pair of spaced valve members secured thereto, and rotatable therewith, each controlling valve ports at difl'erent times, means for actuating said valve, and means automatically controlled by move ment of said ram for operating said actuating means,

5. In pneumatic hammer mechanism, a ram reciprocating vertically, means for actuating the ram comprising a piston and cylinder, and a valve for controlling the flow of a compressed medium into and out of said cylinder comprising a horizontally disposed rotatable shaft having a pair of spaced valve members secured thereto and rotatable therewith, each controlling valve ports at different times.

6. In pneumatic hammer mechanism, a ram reciprocating vertically, means for actuating the ram comprising a piston and cylinder, a valve forcontrolling the flow of a compressed medium into and out of said cylinder comprising a horizontally disposed rotatable shaft having a pair of spaced valve members secured thereto and rotatable therewith, each controlling valve ports at different times, and a chamber communicatin with said valve and a portion of said cy inder, said chamber being arranged to retain therein a predetermined amount of the compressed medium to serve as a cushion 7 for the ram.- v

7. In pneumatic hammer mechanism, a ram reciprocating in one lane, means for actuating the ram comprism a piston and cylinder, a valve for controlling the flow ofa compressed medium into and out of said cylinder comprising a horizontally disposed rotatable shaft having a pair of spaced valve members secured thereto and rotatable therewith, each controlling valve ports at 30 different times, and a chamber communicating with said valve and a portion of 'said cylinder, said-chamber bein arranged to retain therein a predetermine amount of the compressed medium to serve as'a cushion for the ram.

8. A pneumatic hammer mechanism comprising a ram slidably mounted to reciprocate in a vertical plane, means for raisin the ram comprising a cylinder positione above the ram, a piston within sald cylinder and operatively connected with the ram, and valve mechanism for controlling the flow of compressed fluid into said cylinder whereby the'piston may be raised, and for exhausting said cylinder to permit the ram to .drop, said valve mechanism including a chamber for conducting compressed fluid to and from the cylinder when any of the valve ports are open and for retaining a portion of the compressed fluid so as to serve as a cushion when the valve ports are closed.

9. A pneumatic hammer mechanism comprising a ram slidably mounted to reciprocate in a vertical plane, means for raising the ram comprising a cylinder positioned above the ram, a piston within said cylinder and operatively connected with the ram, and valve mechanism for controlling the flow of compressed fluid into said cylinder whereby the piston may be raised, and for exhausting said cylinder to permit the ram to drop, said valve including a chamber for conducting compressed fluid to and from the cylinder when any of the valve ports are open and for retaining a portion of the compressed fluid so as to serve as a cushion when the valve ports are closed, and said valve mechanism also includes movable members cooperating with the ram comprising a cylinder positioned the pressure of comabove the ram, a piston within said cylinder and operatively connected with the ram, valve mechanism including movable valve members for controlling the flow of compressed fluid into said cylinder whereby the piston may be raised, and for exhausting said cylinder to permit the ram to drop, and a casing forming a chamber to conduct compressed fluid to said valve mechanism for retaining a portion of the compressed fluid, said movable valve members being acted upon by the retained, compressed fluid to maintain at least one of the said valves effectively closed by the pressure of compressed fluid within said chamber.

11. In pneumatic hammer mechanism, the combination of a movable weight, a cylinder, a piston within the cylinder 0peratively connected to the weight, and a chamber communicating with the cylinder for maintaining compressed fluid to serve as a cushion.

12. In pneumatic hammer mechanism, the combinatmn of a ram and cylinder and a piston within the cylinder operatively connected with the ram, a source of compressed fluid and a rotary valve having a plurality of ports for controlling the flow of compressed fluid to and from said cylinder constructed to open said valve ports at the same speed. Y

13. In pneumatic hammer mechanism, the combination of a ram and cylinder and a piston within the cylinder operatively connected with the ram, a source of compressed fluid and a rotary valve having a plurality of ports for controlling the flow of compressed fluid to and from said cylinder constructed to open said valve ports at substantially a constant rate of speed.

14. In neumatic hammer mechanism, the combination of a movable weight, an operating' mechanism for reciprocating said weight comprising a valve housing having a relatively flat transverse perforated partition, a flange member secured to said housing, said flange member having a relatively 7' fiat perforated face substantially parallel to said transverse partition and spaced therefrom, a rotatable shaft extending through said partition and said face, said shaft having relatively flat discs secured thereto proximate said partition and said face, re-

spectively, and arranged when in one position to effectively seal the perforations therein, one of said discs having perforations arranged so that When said shaft and disc are rotated into a second position a passa e is opened therethrough and the other aving perforations arranged so that when said shaft and disc are rotated into a third position a passage is opened therethrough.

15. In a pneumatic hammer mechanism a ram reciprocating in one plane and means for actuating the ram comprising a piston, cylinder and valve mechanism, said valve mechanism including a valve housing for a relatively flat, transverse, perforated par tition, a flange membersecured to said housing, said flange member having a rel atively flat perforated face substantially parallel to said transverse partition and spaced therefrom, a rotatable shaft extending through said partition and said face, said shaft having relatively flat discs secured thereto proximate said partition and said face, respectively, and arranged when in one position to effectively seal the perforation therein, one of said discs having perforations arranged so that when said shaft and disc are rotated into a second position a passage'is opened therethrough and the other having perforations arranged so that when said shaft and disc are ro tated into a third position a passage is opened therethrough.

' 16. In a pneumatic hammer mechanism, a ram reciprocating vertically, means for actuating the ram comprising a piston, cylinder, and valve mechanisms, said valve mechanism including a horizontally disposed rotatable shaft having a pair of spaced valve members secured thereto, each controlling valve ports at different times and including also a valve housing having a relatively flat transverse perforated partition, a flange member secured to said housing said flange member having a relatively flat, perforated face, substantially parallel to said transverse artition spaced therefrom, said flange mem ers being positioned adjacent said partition and said flan e member respectively.

S1 ed at Providence in the county of Providence and State of Rhode Island, this 27th day of October, A. D. 1922.

GEORGE P. MAGREADY. 'WILLIAM I. SEYMOUR. 

